Incomplete Maverick Panic Reports

[Bjoern Kahl]

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Dear All,

in the past days we received a number of Panic Reports from users
running Maverick and the old stable 74. - Thanks to all who sent these!

Unfortunately, they were missing he one crucial bit of information
needed to make sense from the data: The load addresses of the loaded
kernel modules.

Has Apple changed the (default?) panic report format in Maverick?

Example Panic Report (shortened & anonymized)

> Anonymous UUID: x-y-z-a-b
>
> Sat Nov 23 xx:yy:zz aaaa panic(cpu 4 caller 0xffffff80002dc19e):
> Kernel trap at 0xffffff80003fb054, type 14=page fault, registers:
> CR0: 0x0000000080010033, CR2: 0x00000000000000d0, CR3:
> 0x00000003b690e043, CR4: 0x00000000001606e0 RAX:
> 0x0000000000000000, RBX: 0x0000000000000000, RCX:
> 0xffffff80008e2b20, RDX: 0xffffff80359fd780 [ more registers - ok
> ]
>
> Backtrace (CPU 4), Frame : Return Address 0xffffff81da49b8b0 :
> 0xffffff8000222f69 0xffffff81da49b930 : 0xffffff80002dc19e [ more
> frames - ok ]
>
> [ *missing* section: "Kernel Extensions in backtrace" - bad ]
>
> [ more info , e.g. thread name, version infos etc. - ok ]
>
> System uptime in nanoseconds: 5444806004610 last loaded kext at
> 351715485611: com.apple.driver.xx 80.14 (addr 0xffffff7f81fd4000,
> size 73728) last unloaded kext at 448942783569:
> com.apple.filesystems.xx 1.9 (addr 0xffffff7f81f4d000, size 57344)
> loaded kexts: org.maczfs.zfs.fs 74.3.1 com.xx.yy 2.0 com.xx.yy
> 1.5.2 [ more kext names & version info ]

As one can see, the load address of the loaded kexts is missing. So
it is impossible to find out where the crash really happened.

Earlier Panic Reports had an extra section "Kernel Extensions in
backtrace" reporting the load addresses of kexts involved in the
crash.

Has this part been removed from the (default?) report format, or is
Maverick just spending to much work in reporting the problem, such
that the interesting frames are no longer in the backtrace and
therefore has no kext load addresses to report, because no recorded
frame address is in a kext?

Actually, I have one single Maverick Panic Report with 12 frames
reported and the needed section "Kernel Extensions in backtrace"
present. All other reports have only 7 frames.

Q:

Does anyone know if there is a way to make Maverick by default report
the full backtrace including load addresses of kexts loaded and in the
backtrace? Is there a tunable on how many frames to report at most?

Or could it really be the case that all reported Maverick crashes
except one really had not gone through MacZFS code prior to panicing?


Since I don't have Maverick I can't reproduce reported crashes and so
need usable Panic Reports to investigate problems.


Thanks

Björn

- --
| Bjoern Kahl +++ Siegburg +++ Germany |
| "googlelogin@-my-domain-" +++ www.bjoern-kahl.de |
| Languages: German, English, Ancient Latin (a bit :-)) |
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[Graham Perrin]

On Sunday, 24 November 2013 10:24:06 UTC, BjoKaSH wrote:

 

… Has Apple changed the (default?) panic report format in Maverick? …

 

> [ *missing* section: "Kernel Extensions in backtrace" - bad ]

What you describe is probably not Mavericks-specific.

Unrelated to Mavericks or MacZFS: for reference only, there's a 12F45 example (without kernel extensions in backtrace) at <http://pastebin.com/HtsU2XR3>. 

Regards

Graham